I used the Boppy a lot to the point I purchased additional covers for it so I could always have a clean one handy. It was very helpful because our son had GERD/Reflux disease and had to be propped up for 30 minutes after each feeding. At first it was a bit hard to use until I got a good position down, but after a while your back with hurt or your arm needs positioning and it's just nice to have something that wedges around you or to you rather than a pillow that won't position right.
I also used it later to prop him up on and also wedged around him when he was learning to sit up properly (all with supervision of course). It was also nice to use prior to having him because I could wedge it under my stomach for extra support of my huge belly.
You can find them cheap at yard sales and consignment shops as well, mine was second hand but obviously not used much. I just washed it according to instructions and then purchased a cover for it. They have very nice covers in all sorts of prints and reversable and the like. I'd put it on my wishlist.